1. The Field of the Invention
This invention relates to endoscopes and endoscopic procedures. More specifically, this invention relates to systems and methods for maintaining a clear visual field during endoscopic procedures and, in particular, during nasal sinus endoscopic procedures.
2. The Background Art
In order to examine an interior bodily organ or region, an endoscope is commonly used. Generally speaking, an endoscope is a rigid or semi-rigid device comprising an optical system. One end of the endoscope is adapted to be inserted into the organ or region to be examined, and a light transmission system is also typically incorporated to illuminate the organ or region. The physician can thus perform the necessary bodily examination by looking through the endoscope.
Following an endoscopic examination, a physician may determine that surgery is required. The surgeon may then use an endoscope to view the surgical site, while at the same time performing the surgical procedure with appropriate surgical instruments. In this way, the surgeon is able to perform the required operation using forceps, scissors, knives, or other surgical instruments, while continuously observing the operation through the endoscope.
During endoscopic procedures of the type outlined above, it is common for the lens or viewing window of the scope to become periodically obstructed by blood or other body fluids or by tissue fragments or fog. Of course, it is then necessary to clear the visual field before the examination or surgery can continue.
A typical way to maintain a clear visual field during endoscopic procedures is to periodically remove the endoscope from the body and wash or wipe the endoscope's viewing lens. The endoscope can thereafter be reinserted into the body, and the examination or surgery can continue. Unfortunately, however, this relatively simple procedure suffers from a number of significant disadvantages.
For example, in using the above-outlined procedure, a surgeon must periodically interrupt the examination or surgery in order to clear the visual field. The endoscope must then be carefully repositioned in the patient's body before the examination or surgery can continue As a result, the examination or surgery is prolonged. In addition, due to the fact that the proper insertion and placement of an endoscope is usually somewhat delicate, the repeated removal and reinsertion of the endoscope poses a significantly increased risk of injuring the patient.
Further, maintaining a clear visual field in the manner described above is quite awkward. Surgical instruments may tend to get in the way. Moreover, the surgeon's attention becomes divided, and the surgeon is forced to focus a significant amount of attention on the instruments and equipment being used, rather than on the surgical procedures being performed.
In an effort to alleviate some of the foregoing concerns, those skilled in the art have developed endoscopes and endoscope accessories which include integral irrigation and/or suction channels. During nasal sinus endoscopic procedures, for example, it is common to employ a sheath surrounding the endoscope through which an irrigation fluid may be injected so as to clear the visual field. Although many surgeons seem to prefer such devices to the use of the conventional techniques described above, significant drawbacks remain.
The need to operate a separate mechanism associated with the endoscope in order to clear the visual field still typically requires the surgeon's attention, thus still requiring the periodic interruption of the examination or surgery. Additionally, many available suction/irrigation mechanisms are somewhat complicated, making them both difficult and/or time consuming to assemble and awkward and difficult to handle during use. This again results in an increase in the time required for the examination or surgery and in a need for the surgeon to devote significant surgical time and attention to instrumentation.
In addition, the use of integral irrigation/suction systems can increase the diameter of the endoscope, which, in some cases, can become a significant disadvantage. During nasal sinus endoscopic procedures, for example, surgical space is very limited. Surgical instruments are typically four to five millimeters in diameter, while a typical endoscope may be from about two and one-half to about four millimeters in diameter. The use of a separate irrigating sheath which will, of course, further increase the size of the endoscope may thus significantly restrict the scope's access to and/or movement within the surgical site and, as a result, limit the scope's viewing area and ultimate effectiveness.
Irrigation sheaths and similar accessories for endoscopes can also be relatively bulky and heavy. This often makes the scope hard to control and may, consequently, increase the potential risk that the scope may penetrate and cause injury to an adjacent organ or bodily region. The increased weight of the scope also accelerates hand fatigue during surgery, and, when using such devices, it is not uncommon for a surgeon's had to begin shaking with fatigue before the surgery is completed.
Further, the prior art irrigation/suction accessories for integral use with endoscopes are usually quite expensive. Being non-disposable, they must also be sterilized prior to each use. Also, careful maintenance is required, since the use of conventional saline irrigation solutions renders the metal parts highly susceptible to rust. This further increases the cost and inconvenience of such devices.